Ink jet printheads are composite structures which are conventionally made by bonding a nozzle plate to a semiconductor substrate either directly using an adhesive or by bonding the nozzle plate to a polymeric layer which is deposited on or bonded to the substrate. The polymeric layer may be patterned before or after bonding to the substrate in order to provide ink flow features which provide ink to the regions of the printhead which induce the ink to be expelled through the nozzle plate to a print media.
In order to bond a nozzle plate to the polymeric layer, heat and pressure are applied to the nozzle plate and substrate. Because each of the nozzle plate, polymeric layer, and substrate material often have a different modulus of elasticity and coefficient of thermal expansion, the materials of the printhead composite tend to expand and contract at different rates and by different amounts when heated and/or cooled. The uneven expansion and/or contraction of the components during the bonding process induce stresses which warp the components thereby causing misalignment and stresses which increases the tendency for the components to fracture during assembly and use of the printhead. Component misalignment and/or warpage may result in misfiring of the printhead or in ink being misdirected from the printhead.
As the number of nozzle holes increases and the size of the holes decreases, the criticality of component alignment becomes substantially more important for the proper functioning of the printer. Printhead structures which are warped or which contain components which are not aligned properly result in significantly reduced printer performance and quality.
An object of the invention is to improve component alignment in a printhead structure.
Another object of the invention is to reduce thermal stresses in print head components during assembly thereof.
A further object of the invention is to provide a less costly manufacturing process for printhead components which induces relatively less thermal stresses in the components parts thereof.